DE2026031B2 - Process for the production of organic carboxylic acids - Google Patents

Description

HCOOR

wherein R has the meaning given above, in the presence of carbon monoxide and one Catalyst consisting of a metal or a metal compound from group Hb or VIII des Periodic table in an organic polar solvent, consisting of carboxamides, heterocyclic amines, nitriles or ketones, Hei a temperature ve η 100 to 300 ° C and below heated under increased pressure.

The reaction according to the invention is expressed by the following reaction scheme:

HCOOR

(CO)

RCOOH

(IH)

The invention relates to a process for the preparation of a carboxylic acid of the general formula

RCOOH

wherein R is a saturated or unsaturated, acyclic or cyclic aliphatic hydrocarbon group, aryl, aralkyl or heterocyclic group.

Various methods for the synthesis of organic carboxylic acids are known, but none has been found to date Reaction of the direct conversion of a formic acid ester HCOOR to a corresponding organic one Carboxylic acid known as RCOOH.

It is also known to convert methyl formate to acetic acid at an elevated temperature in the presence of metals of the VIII. Group of the Periodic Table and a free halogen to isomerize. In this procedure however, temperatures of over 300 ° C. are required in order to obtain acceptable yields. In addition, various side reactions occur in the known process, so that the isolation the desired organic acid can be technically complex and also the starting material used and the catalysts can hardly be recovered.

The object of the invention is to produce organic carboxylic acids of the general formula given technically simple manner in good yield and in pure form and avoiding side reactions to manufacture.

Based on the above reaction scheme, carbon monoxide does not seem to take part in the reaction, however, it is essential according to the invention to carry out the process under the increased pressure of carbon monoxide perform.

As radicals R in the formic acid ester HCOOR, which is used as the starting material according to the invention is to be used, alkyl radicals with 1 to 6 carbon atoms, preferably methyl, ethyl, n-propyl, Iso-propyl, η-butyl, isobutyl, sec-butyl, ten-butyl, amyl and isoamyl radicals; unsaturated AlkyMAlkenyl and alkynyl -) - radicals with 2 to 6 carbon atoms, such as vinyl, allyl and propargyl radicals; alicyclic hydrocarbon radicals with 4 to 10 carbon atoms, such as cyclobutyl, cyclopentyl, cyclohexyl, Methylcyclohexyl and cyclohexenyl radicals; acyclic or cyclic terpene radicals having 5 to 15 carbon atoms; Aryl radicals having 6 to 12 carbon atoms, such as phenyl, tolyl and xylyl radicals; Aralkyl radicals with 7 to 14 carbon atoms, such as benzyl, methylbenzyl and phenethyl radicals and 5- or 6-membered heterocyclic radicals with 4 to 10 carbon atoms, such as pyridyl, methylpyridyl, furyl-piperidyl and indolyl radicals can be mentioned.

The formic acid esters which can be used advantageously according to the invention, include lower alkyl esters, unsaturated lower allyl esters, cycloalkyl esters and aralkyl esters Formic acid. According to the invention, the term “lower” is understood to mean: “with 1 to 4 carbon atoms”.

According to the invention, carbon monoxide can be used alone or in admixture with an inert gas. There can be a small amount of hydrogen in carbon monoxide or its mixture with an inert gas be included. The required application of increased pressure of carbon monoxide does not promote only the reaction according to reaction scheme (III), but also prevents the decomposition of the formic acid ester according to the following reaction schemes:

HCOOR - HR + CO ₂
HCOOR - ROH + CO

(IV)

As the reaction rate at one pressure

of less than 80 atmospheres are comparatively low, a salt of a halogenoxy acid or a Komi is particularly preferred to use carbon monoxide under a complex of an organic onium compound or under pressure of more than 80 atmospheres. The higher the form of a mixture containing, for example, the pressure, the more the decomposition of a combination of (A), (a) a metal, (b) a formic acid ester and the higher the organic acid salt, (c) one / J-diketone or reaction rate. With regard to a host / 3-keto acid ester complex, (d) a hydroxide, economic implementation, however, it is advantageous to carry out the (e) a carbonate, (f) a bicarbonate, ig) a reaction under a pressure of 150 to 700 kg / cm ^{2 of} nitrate, (h) a sulphate, (i) an oxide or (j) a (manometer). If a mixture of a carbonyl compound of a metal from group VIII carbon monoxide with an inert gas and / or water io of the periodic table and (B), (a ') a molecular substance is used, it is sufficient to use the partial halogen, (b) a Hydrogen halide acid, (c ') a pressure of carbon monoxide at 50 to 300 kg / cm ² alkali or alkaline earth metal halide or ^ d') a HaIo- (manometer) to keep. It is sufficient to introduce carbon oxyacid or its alkali or alkaline earth metal salt, monoxide in such a way that the pressure is kept within the above range, and there is no need for acid, bromic acid, chloric acid and perbromic acid , Carbon monoxide can be used in equimolar halogenoxy acids. Amount based on the starting formic acid ester, although the amount of catalyst used, to introduce. which is a metal of Group VIII of the Periodic Table

At higher temperatures a's 300 ⁰ C which contains, depends on the type of K? * Alysators, is

Tendency for side reactions to occur. Usually the catalyst according to the invention is preferred

preferred temperatures are within a range in an amount of 0.2 to 200 mg atoms, preferably

from 180 to 300 ⁰ C. wise 5 to 30 mg atoms, calculated as metal, each

Suitable catalysts are used to convert one mole of the starting formic acid ester. if

Formic acid ester to a corresponding orga- π an in the catalyst halogen provides, the Halo-

Niche carboxylic acids are metals or metal counterpart components in an amount of 0.1 to 5C0 mg

bonds of groups Hb or VIII of the period atoms, preferably 1 to 80 mg atoms. calculated

systems. as halogen atom, per mole of starting formic acid

Metals of the esters can be used as catalysts of this type. The use of the components Group VIII of the periodic table, such as iron, cobalt metal and halogen above the stated upper limit and nickel and compounds of these metals, moreover, does not affect the reaction, but is are used, whereby the metal compounds are organically not advantageous, niche acid salts, hydroxides, carbonates, bicarbo- According to the invention it is possible in place of the nates, nitrates, sulfates, oxides, salts of a halogenoxy- the above-mentioned catalysts with a content acid, complex compounds of organic onium on a metal of group VIII of the periodic compounds, Halides and carbonyl compounds 35 systems also catalysts that are a metal of the group (containing carbonyl hydride) of metals of group Hb of the periodic table, effective for Um-VIII de? Periodic table and complex compounds put formic acid esters to the corresponding such salts with / J-diketones, or / 9-keto acid organic carboxylic acids to be used. Under are esters. Acetates or propionates can be used as these catalysts, a mercury enthalorganic Acid salt can be used. A salt 40 tender according to the invention is very advantageous for the association Metal of group VIII of the periodic table. As a catalyst from group Hb with an organic of the periodic table to be formed by the reaction can (a) a metal per se (a-carboxylic acid is particularly preferred. As a metal - finally amalgam), (b) an organic acid salt, complex compound with a / 9-diketone or a (c) a / J-diketone or / 9-keto acid ester complex, / 9-keto acid esters can be complex salts of a metal 45 (d) a hydroxide, (e) a carbonate, (f) a bicarbonate, of group VIII of the periodic table with acetyl- (g) a nitrate, (h) a sulfate, (i) an oxide, (j) a salt acetone or ethyl acetoacetate can be used. As of halooxy acid, (k) a complex compound Complex compound of organic onium compounds of an organic onium compound or (1) can, for example, di- [butylpyridinium] cobalt halide of a metal from the group Hb d ^ s period tetrabromide, Di-tetraethylammonium / nickel tetra- 50 systems can be used. These connections one iodide and di- [tetramethylammonium] cobalt diiodide metal of group lib of the periodic table are, diacetate can be used. although the metal is polyvalent, not on connec-

These compounds of metals of group VIII fertilize with a special valence limited. Example

of the periodic table, although the metal can be made up of both mercury compounds

is valuable, not used on compounds with a special 55 mercuro- and mercuric compounds

Limited value. For example, can be made of iron.

Both ferrous and remote compounds used catalysts, which are a halogen as well as a

will. Metal from group lib of the periodic table

It has been found that under the above hold, are particularly preferred as metal ent-

mentioned group of catalysts those which use 60 holding catalysts,

a metal of Group VIII of the Periodic Table and soils according to the invention are preferred

contain a halogen, particularly effective for converting halides, salts of a halogenoxy acid or compo-

Conversion of formic acid esters to the corresponding plexes of an organic onium compound

the organic carboxylic acids in the case of a high metal from group Hb of the periodic table and

Sales are. Such catalysts, which the 65 combinations of (A), (a) a metal, (b) a

Metal and a halogen can contain either organic acid salt, (c) a / 3-diketone or

present in the form of a halide, such as cobalt iodide, / 3-keto acid ester compiex, (d) a hydroxide,

Nickel iodide, cobalt bromide and cobalt chloride, or (e) a carbonate, (f) a bicarbonate, (g) a

5 6

Nitrate, (h) a sulfate or (i) an oxide to use one, namely those which are caused by the

t metal of group Hb of the periodic table and (B) formula

(a ') a molecular halogen, (b') a halogen R '

r hydroic acid, (c ') an alkali or alkaline earth RTDN

halide or (d ') a halogenoxy acid or its 5 v_uin _v

Alkali or alkaline earth salt used. R "

The same thing with regards to the catalyst

a content of a metal of Group VIII des are characterized, in which R is the above

• Periodic table has been described, applies to the given meaning and R 'and R "for a

Catalyst, which is a metal from group Hb of the io straight-chain lower alkyl group.

Periodic table contains, regarding the applied Since the use of a cyclic amide does not

Amounts of a metal from group Hb of the period- the formation of an organic carboxylic acid cnt-

j systems and halogen too. speaking of the acyl group of the amide solvent

S If a catalyst that produces a group metal as a by-product through acyl group exchange

! VIII of the periodic table, caused by a catalytic reaction, it is in the method according to

is compared to a metal of the group Hb of the invention is particularly preferred, a cyclic

j of the periodic table, the former is to be used in the all-amide.

j common the latter with regard to catalytic activity Although by using the solvent in

j consider. Furthermore, if according to the invention too large an amount, there is no particular disadvantage in the

j a halogen is used in the catalyst does not cause the reaction of the invention to run

j is only possible when the reaction speed becomes considerable, are troublesome operations for removal

lent to activate, but generally also that of the solvent is required. On the other hand it is Solubility of the metal used as a catalyst if the amount of solvent used is too small,

> to increase in the reaction mixture. scary to dissolve the catalyst sufficiently.

\ It has been found that the invention as Accordingly, it is suitable according to the invention, the

! Reaction can be activated strongly if one uses as a solvent in an amount of 0.2 to 10 mol each

Solvent to use an organic compound of high moles of the starting formic acid ester.

Polarity used in which the method according to the invention can sometimes

The catalyst to be used is soluble. the side reaction expressed by the above

Such solvents are preferably dipolar, reaction scheme (V) listed, occur, depending on aprotic solvents, for example amides, as the reaction conditions. In such a case Formamide, N-methylformamide, Ν, Ν-dimethylform- the by-product ROH reacts with the resulting amide, acetamide, N-methylacetamide, Ν, Ν-dimethyl organic carboxylic acid RCOOH to form the acetamide and N, N-dimethylpropionamide; cyclic by-product RCOOR, which in the product

Amides, such as α-pyrrolidone, N-methylpyrrolidone, «-Pi- 35 liquid is included. It was found that the peridon and N-methylpiperidone; as well as nitriles, as mentioned side reaction almost completely due to acetonitrile and propionitrile. There can also be a very small amount of RCOOR to the heterogeneous cyclic compounds can be used, such as pyri starting material in advance, e.g. 0.005 to din, picoline, piperidine and morpholine and ketones 0.1 mol per mole of the starting formic acid ester.

high boiling point, such as acetophenone. Preferred 40 can be inhibited.

wise leads the catalyst as a solution in a The process of the invention can either

the above-mentioned solvents in the reaction are carried out continuously or batchwise, mix one. however, better results can be achieved through continuous

In the method of the invention, it can be obtained when the method is carried out. Turning a solvent with a higher 45. If the reaction is carried out by means of a continuous boiling point than that of the desired organic process, the liquid carboxylic acid is possible, the desired organic space velocity 0.1 to 10 h " ¹ , preferably acid from the reaction mixture by distillation 0.5 to 5 h ^-1 .

to win, with the catalyst in the form of a The drawing represents a flow diagram, which

Solution in the organic, polar 50 used is an embodiment of the method of the invention Solvent remains. Since such a solution is explained, the process being continuously expanded Catalyst in the solvent in the Reak leads.

The process of the invention is described below

holt can be used, the use is more detailed with reference to the drawing Solvent with such a high boiling point 55 refines.

advantageous when the process of the invention The starting formic acid ester is in the react

should be run continuously. tion pipe 7 from tank 1 through line 2

When the above-mentioned amides as Lö- leads. The catalyst is in the form of a solution Solvents are used, the acyl group in a solvent, if a solvent Exchange reaction is used partially between the solution 60, or a solution in the product medium and the resulting organic carbon liquid, if the reaction is carried out without application acid, which is carried out to form an amide of a solvent, from the memory the resulting organic carboxylic acid and a container 3 with the catalyst solution through line ' organic carboxylic acid, corresponding to the acyl introduced into the reaction tube 7. Carbon monoxyc group of the solvent, leads. Accordingly, it is 65 into the reaction tube 7 from the pressure vessel f if amides are used as solvents, and line 6 introduced in such a way that the Reak «^ Wishes amides corresponding to the acyl group of the tion tube 7 with increased Kohienmonoxyddnici desired organic carboxylic acid (RCOOH) is maintained. Carbon monoxide, which is out of lead!

55SSSSSSS

Line 12 and is led to column 15 for the separation and recovery of catalyst and solvent. The column AJ Mst a harvested t. Distillation column. The Katag ° ^and J _ne ;

Me, h _{? LTO} , a «w ^ hoU will. _{te [äe} . the 7 /, 5> / "·

B e i s ρ ι e 1 2

executed, but with the modification,

^ SmTÄÄ

from the top of the column is mainly composed of the organic carboxylic acid formed, however contains unreacted ^ Am ™ acid esters and in some cases wine quantities Esters as formic acid esters and alcohols are formed as by-products · The the rectifying column 19 is durchuden ^ Radiator 17 and line 18 trains £ * «J J converted formic acid ester becomes in the colon

ne head "recovered ^un J ^ ⁶ 3 24, to the line 2 ^ ™ f" by the selective ^ ^{u 'serial} then in the üonsg ^ ^ j ^ «« nimen with gangsameisensaureester eingefuJ ". A carboxylic acid with a purity, which is the end product, is distilled at "^^" ^ above the column bottom obtained through cooler and line 21 ^ and then the product tank 22 is stored. If betracntiicne ^ ι enfcc esters other than Ameisensäureester odter alcohols in the distillate line 24 m entha th Sindl "ground-products geb.ldete There he" g ^ ^A J recovered by a far ^ere ^ ¹ ^^.

In

_a5

30th

Sr ^ rtXIn SS £ ÄSE dS leads and inhibits undesired side reactions, such as the decomposition of the form saweester, used. The reaction tube can either of the liquid-gas parallel flow type or of the liquid-

Be gas countercurrent.

According to the invention ^ '^ J ^ I Sense acid esters can easily be identified by the well-known M

Accordingly, it is produced by the Method of .invention TÄt ™ SSn

Carboxylic acids «« «ί ^, Τ ^ Ϊ! ¹ ^ SSn "Organic carboxylic acids ^ conversions of the order of 90% or less can be achieved

getting produced. individual through

The invention is detailed below

Examples explained in more detail.

B e i s ρ i e; 1

A shaking autoclave from ^ interior capacity of 100 ml (0 233 mol) M ^

⁹³ ; Scht ^{based on the starting methyl formate}

is equivalent to.

Example 3 ^ ^ _{the continuous ver} .

Application of a reaction tube

_{em StaM with an interior space of 300 m} l,

_mm ^ ^^. ^^ _by _

^ ™ _{ser v} * _{n 30 nmi} carried out. The feedback ™ _{sjnd wjc f <j,. Dnick} ^ _{atii> Tem}

^ 8 introduced amount of methyl formate 365 g _{per hour (6,} 08 moles per hour), Flüssigraumgeschwin- ^J _{di ness} J ^ -i _{25 h and} guided in circulation amount ^ _{h] enm; noxyd 89} Nl / h (4.0 mol per hour). N-methylacetamide is used as the solvent at a rate of 0.92 mol per mol of Methy'Ormiat ÄhHnd as a catalyst is cobalt iodide in eg, 0.022 mol per mol of methyl

«N ^ ^^ ^ _{N. Methylacetam} i _{d solution} ,

Weight percent cobalt iodide) contained ^ ^ _{j WQche continued}

'«" _{A yield of 337 per hour}

fs 62 moles per hour). This yield ent _{MPLIANCEWITH a} ^J _em turnover of 92.3 "/", based on the imported Methylformia,

B e i s ρ i e 1 4

lilfgio.02Mol) The reaction is carried out for 48 hours using the same reaction vessel as in Example 3 under the following conditions: pressure 400 atmospheres, temperature 230 ^c C, feed rate of methyl formate 366 g per hour (6.10Mol j <hour), liquid space velocity 1.25 h " ¹ and carbon monoxide circulation rate 98 Nl / 1 (4.38 mol per hour). The solvent is N-methylpyirolidone at a rate of 1.0 Mo per mole of methyl formate and the catalyst is cobalt acetate and iodine in a ratio of 0.020 mole per mole of methyl formate in the form of a solution in N-methylpyrrolidone, wetehes as a solvent is used. As an addition, we also introduce methyl acetate at a rate of 11 g per hour (0.15 mol per hour). The result is acetic acid in a yield of 347 g per hour (5.77 mol per hour). This yield corresponds to a conversion of 94, T ⁰ I ₀ , tx added to the methyl formate introduced

Example 5

The reaction is carried out using the same reaction vessel as in Example 3, continuously for 48 hours under the following conditions: pressure 300 atm. Temperature 230 ⁰ C, feed rate of methyl formate 304 g per hour (5.07 mol per hour), liquid space velocity 1.04 h- ¹ , circulation rate of carbon monoxide gas with a content of 3 percent by volume of hydrogen 102 Nl / h (4.42 mol per hour Hour, calculated as carbon monoxide). N-methylpyrrolidone is introduced as solvent in a ratio of 1.04 mol per mol of methyl formate, and cobalt iodide is introduced as catalyst in a ratio of 0.018 mol per mol of methyl formate (in the form of an N-methylpyrrolidone solution, contains 5.18 percent by weight cobalt iodide). As a result, acetic acid is obtained in a yield of vo g per hour (4.62 mol per hour). This yield corresponds to a conversion of 91.3% based on the methyl formate introduced.

Examples 6 to 10

Experiments are carried out in the same reaction vessel as in Example 3, changing the type Alkyl radical of the formic acid ester, the type of solvent, the type of catalyst and others Reaction conditions carried out. The results of each experiment are in the table below listed.

Table I.

Example! No. 8th

10

R of formic acid ester HCOOR

Feed rate of the formic acid ester

g / h

Moles / h

Liquid space velocity, h ^-1

solvent
Art

Amount (moles per mole of HCOO) R

catalyst
Art

Amount (moles per mole of HCOOR)

Concentration of the catalyst solution, (%)

Rate of circulation of carbon monoxide

Nl / h

Moles / h

Temperature, ( ⁰ Q

Pressure, (atü)

Duration of continuous operation, (hours)

Organic carboxylic acid RCOOH space-time yield

g / h

Moles / h

Conversion, % (based on initial HCOOR)

CH, -

323 5.38

1.1 acetonitrile

2.3

Cobalt acetate

0.020 potassium iodide

0.048 3.74 *)

82 3.66

220 400

10

260 4.34

80.6

CH ₃ -

300 5.0

1.03

Ν, Ν-Di-

methyl-

acetamide

1.0

Cobalt carbonyl

0.019

molecular iodine

0.019 1.25 **)

108 4.8

220 300

48

271 4.51

90.2 CH ₃ CHn-

254
3.43

0.81

N ₁ N-dimethyl propionamide
1.26

Cobalt iodide

0.027

6.24

85
3.8

240
400

24

204
2.75

80.2

CH ₃

CH ₃

220
2.5

0.72

N ₁ N -dimethylbutyramide
1.5

Nickel iodide

0.040

255 2.9

1.03

N-methylpyrrolidone

1.05

Cobalt bromide

0.028

6.76

56
2.5

250
420

137
1.56

62.3

5.45

96 4.29

210 300

12th

195 2.22

76.5

*> Calculated as the cobalt acetate concentration in the catalyst solution. **) Calculated from cobalt meta concentration in the catalyst solution.

" I

Example 11 acid in a yield of 75.0 g per hour (1.01 mol

per hour). This yield equals one

A stainless steel shaking autoclave with a conversion of 29.5%, based on the

an interior space of 100 ml is formate with 20 g (0.147 mol). If the reaction is among the same

Benzyl formate, 20 g (0.202 mol) N-methylpyrrolidone 5 conditions without adding ethyl propionate again-

as a solvent and 1.7 g (0.0054 mol) of cobalt iodide is obtained, the conversion is about 26%.
charged as a catalyst, and the reaction is carried out at

200 ° C for 2 hours under a pressure of 300 kg / cm ² Example 15

(atü) carbon monoxide run, with phenylacetic acid in a yield of 14.6 g (0.107 mol) er io A stainless steel shaking autoclave with a

is procreated. This yield corresponds to an interior conversion of 100 ml with 20 g of methyl formate

of 73%, based on benzyl formate. and 20 g of N-methyl-2-pyrrolidone as a solvent

. -in charged, and 2 g of mercury iodide are added.

B e ι s ρ ι e 1 12 _D j _e R _ea is ction for 1 hour at 220 ⁰ C and a

The same reaction vessel as in Example 11 was carried out at a carbon monoxide pressure of 300 atmospheres. To

is added with 20 g (0.122 mol) of 2,5-dimethylbenzyl formate, termination of the reaction, the autoclave is cooled

15 g (0.151 mol) of N-methylpyrrolidone as a solution and the reaction product removed therefrom. The end-

mitM and 1.2 g (0.0038 mol) of cobalt iodide as catalyz precipitates are separated off by filtration, and

charged sator and the reaction under the same the unreacted methyl formate is distilled off.

Conditions as set out in Example 11. 20 Another distillation of the remaining liquid

2,5-dimethylphenylacetic acid in a yield of speed gives acetic acid in a yield of 15.6 g.

13.5 g (0.082 mol) were obtained. This yield corresponds to this yield corresponds to a conversion of 78%.

a conversion of 67.5%, based on the output based on starting methyl formate.
gang formic acid ester.

Examples * ⁵ examples

The reaction is carried out after the continuous The same autoclave as used in Example 15

Method using a reaction tube is applied, 20 g of methyl formate, 20 g

made of stainless steel with an interior of N-methylacetamide, 1.6 g of mercuric acetate and 3.2 g

300 ml, a length of 500 mm and an inner 30 potassium iodide charged. Carbon monoxide is in the

diameter of 30 mm was introduced under the following reaction autoclave under pressure, and the reaction

conditions: temperature 22O ⁰ C, Me is atm at 220 ° C and a pressure of 320 1 hour

ethyl formate feed rate carried out for 302 g per hour. The reaction product is

(5.03 moles per hour), liquid space velocity treatments to produce 16.0 g of acetic acid

1.03 h- \ pressure 400 kg / cm ² (gauge pressure) and 35 subjected. This yield corresponds to an

Carbon monoxide circulation rate 102 Nl / h rate of 80.0%, based on the starting methyl

(4.55 moles per hour). The solvent used is Ν, Ν-di-formate.

methylacetamide in a ratio of 1 mole per mole Example 17
Ethyl formate is introduced and used as a catalyst

Cobalt acetate in a ratio of 0.022 mol per 40. The same autoclave as used in Example 15

MoI methyl formate in the form of a solution in Ν, Ν-Di- was used, with 20 g of ethyl formate, 20 g

methylacetamide introduced. The reaction is 10 hours of N-methyl-2-pyrrolidone and 1.5 g of mercuric bromide

the long run continuously. Acetic acid is sent and carbon monoxide is pressurized

in a yield of 92.0 g per hour (1.35 moles each. The reaction is carried out at a pressure of

Hour). The yield corresponds to around 45 400 atmospheres and at a temperature of 250 ^° C. for 1 hour

rate of 30.4%, based on introduced methyl long carried out. As a result, priopioic acid is in

formate. obtained a yield of 13.0 g, which corresponds to a conversion

_n "· ■, _ΛΛ of 65%, based on the starting ethyl formate

Example 14 corresponds.

The continuous reaction is carried out using 50 Example 18

of the same reaction tube as in Example 13

carried out under the following reaction conditions: The same autoclave as used in Example 15 ver

Was aimed temperature 25O ⁰ C, feed rate of ethyl, is charged with 20 g of benzyl formate, formate 254 g per hour (3.43 moles per hour), and 20 g of liquid N-methyl-2-pyrrolidone and 1.4 g of Mercury space velocity 0.92 h " ¹ , pressure 350 kg / cm ^a 55 iodide are added. Carbon monoxide is introduced into the autoclave under pressure (manometer pressure), gas circulation rate, and the reaction (mixture of 97 volume percent carbon monoxide and tion is at a pressure of 300 atm and eini 3 percent by volume of hydrogen) 89 Nl / h (3.85 mol per temperature of 210 ° C for 2 hours introduced hour, calculated as carbon monoxide) and feed As a result, phenylacetic acid in a yield rate of ethyl propionate as an additive 3 g 60 of 12.6 g are obtained, which corresponds to a conversion of 63% per hour (0.03 mol per hour). The solvent based on the starting benzyl formate is N-methylpyrrolidone in a ratio of.

1.1 moles per mole of ethyl formate and example iv as a catalyst

Cobalt carbonyl in a ratio of 19 mg-A.tom, the same autoclave as used in Example 15 ver

Calculated as metallic cobalt, per mole of ethyl 65 was used, 20 g of methyl formate are charged formate in the form of a solution in N-methylpyrrolidone and 25 g acetonitrile as a solvent and a ( fed. The reaction is continuous for 12 hours. Mixture of 1 g of metallic mercury and 0.5 j As a result, propionic iodine as a catalyst is added to the autoclave

13 14

Carbon monoxide is added to the autoclave under pressure inhibitor. Carbon dioxide is found in the

and the reaction is initiated at a temperature autoclave under pressure. The reaction

door of 230 ⁰ C and a pressure of 330 atü during 3.0 hours at 200 ^c C under a pressure of

run for an hour. The reaction product is carried out at 520 atmospheres, with acrylic acid in one run Acetic acid worked up, the yield of 14.3 g (0.198 mol) in c'ner yield 5. These

g was obtained of 14.5, corresponding to a conversion of yield corresponds to a conversion of 71.5 ° / ₀ sawn

72.5%. based on the starting methyl formate, moved to vinyl formate,
is equivalent to.

Example 20 Example 24

IO

A stainless steel shaking autoclave with the same reaction vessel as used in Example 23

An internal space of 100 ml is used with 20.0 g (0.33 mol), 20.0 g (0.156 mol) of cyclo-methyl formate, 1.0 mol of N-methylpyrrolidone, 0.10 mol of hexyl formate are charged. Further, per mole of cobalt carbonate off and 0.15 mol of potassium iodide are charged per each gan _S i-cyclohexyl each 1.0 moles of 7-methyl picoline MoI. Carbon monoxide gas 15 was added as a solvent and 0.055 mol of iron iodide as a catalyst containing 5 percent by volume of hydrogen. Carbon monoxide is introduced into the autoclave under pressure, and that is introduced into the autoclave under pressure. The reaction is reaction is excluded at 190 ⁰ C for 2 hours, 2.0 hours at 300 ^c C under a pressure of. The reaction pressure is 80 atm. The reac- 610atu carried out. As a result, the cyclohexantione product is worked up, and 20 carboxylic acid is obtained in a yield of 10.3 g (0.081 mol) and 10.2 g of acetic acid (0.170 mol), which is a result. This corresponds to a conversion of 51.5 ⁰ Z ₀ . rate of 51.0%, based on the starting methyl based on starting formic acid ester,
formate, corresponds to.

Example 25
B is ρ ie 1 21 ² 5

A stainless steel shaking autoclave with a

The same reaction vessel as was used in Example 20 with an interior space of 100 ml with 22.5 g (0.150 mol) is charged with 20.0 g (0.333 mol) of methyl 2,3-xylyl formate. In addition, 1.0 mol of formate are charged. In addition, 1.0 mol of Γ .inolin, N-methylpyrrclidone, 0.036 mol of a complex compound 0.03 mol of cobalt hydroxide and 0.03 mol of magnesium bond from diethyl acetone dicarboxylate and cobalt iodide are added per mol of methyl formate. and 0.070 moles of potassium bromate per mole of carbon monoxide gas containing 35 volumes of 2,3-xylyl formate are added to the autoclave. Percent carbon nitrogen into the autoclave under pressure monoxide is introduced into the autoclave under pressure, and the reaction is carried out at 21O ⁰ C leads 1 hour and the reaction is carried out at 27O ⁰ C for long. The reaction pressure is 250 atm. 35 carried out 2.0 hours, with the maximum pressure The reaction product is made up to acetic acid is about 430 atmospheres. After the reaction has ended, which has a yield of 12.0 g (0.200Mol), the autoclave is cooled and the reaction product is obtained, which corresponds to a conversion of 60.1%. The unreacted 2,3-xylyl based on the starting methyl formate corresponds to. formate is distilled off. Another distillation

40 of the product liquid gives 9.60 g (0.064 mol) of 2,3-di-

Example 22 methylbenzoic acid. This yield equals one

Sales of 42.7%, based on the starting

A stainless steel shaking autoclave with a formic acid ester.
Interior space of 100 ml is filled with 20.0 g (0.333 mol)

Charged methyl formate. Furthermore, 1.2 moles 45 B e i s ρ i e 1 26

N-methylpyrrolidone, 0.05 mole rhodium chloride and

0.08 moles of hydrogen iodide per mole of methyl. A stainless steel shaking autoclave with a

formate added. Carbon monoxide is introduced into the interior of 100 ml with 22.0 g (0.179 mol) autoclave under pressure. 4-pyridyl formate is charged to the reaction. In addition, 1.0 mole is carried out at 150 ° C. for one hour. The 50 piperidine as solvent and 0.045 mol nickel maximum reaction pressure is about 200 atm. bicarbonate and 0.050 mol of magnesium iodate as After the reaction has ended, the autoclave catalyst is cooled for each mol of starting formic acid and the reaction product is recovered. ester added. The unreacted methyl formate is introduced into the autoclave under pressure. The reaction is separated by distillation. A further depilation of the ^{liquid remaining for 2.0 hours at 260 c} C and a pressure of 500 atm gives acetic acid in one run. After the reaction has ended, the amount of 4.2 g (0.700 mol), which corresponds to a conversion of the autoclave, is cooled and the reaction product is withdrawn from it at 21.0%, based on the starting methyl formate. The unreacted 4-pyridyl formate corresponds. is distilled off. Another distillation of the

^If ρ ie 1 23 6o remaining liquid results in pyridine-4-carboxylic acid

in a yield of 4.43 g (0.036 mol), correspondingly

A stainless steel shaking autoclave with a conversion of 20.1% based on the initial interior space of 100 ml is filled with 20.0 g (0.278 mol) of formic acid ester.
Vinyl formate charged. In addition, 1.0 mole of N-methyl 65 B is ρ ie 1 e 27 to 31 per mole of vinyl formate used
pyrrolidone as a solvent, 0.05 mol Diftetraäthyl-

ammonium cobalt dibromide iodide as a catalyst Experiments were carried out under carbon monoxide pressure

and 0.02 mol of hydroquinone as polymerization in the same reaction vessel as in Example 22

was used, changing the nature of the other reaction conditions carried out. The Er-alkyl radical of the formic acid ester, the nature of the results of each experiment are given below Solvent, the type of catalyst and Table II listed.

Table II

R of formic acid ester
HCOOR

Introduced formic acid ester

G

Mole

solvent
Art

Amount (moles per mole of HCOOR)

catalyst
Art

Amount (moles per mole of HCOOR)

Temperature, ⁰ C

Pressure, atü

Reaction time, hours

Organic carboxylic acid
yield

G

Mole

Sales,% (based on

gang HCOOR)

Example 32

28 example no.
29

30th

31

CH ₃ -

20.0 0.333

N-methylacetamide

1.0

Nickel nitrate 0.005

Magnesium iodide

0.005

250 400 2.0

7.26 0.121

36.3

CH ₃ CH ₂ -

20.0
0.270

Pyridine 0.6

Cobaite oxide 0.035 iodic acid 0.070
240
300

1.0

8.40
0.113

42.0

CH ₃ CH ₂ CH ₂ -

21.5
0.244

N-methylpyrrolidone
1.0

Cobalt sulfate

0.030
Potassium iodide

0.070
260
250

1.0

4.58
0.052

21.3

CH3CH 2CHo ^

22.0

0.216

N-mettayl pyrrolidone

1.5

Ferric chloride
0.060

250
280
1.0

1.63
0.016

7.4

CH ₃ -

20.0
0.333

N-methylpyrrolidone

1.0

Cobalt iodate 0.030

210
300
1.0

16.8
0.280

84.0

The same autoclave as used in Example 26 is charged with 20.0 g (0.278 mol) of vinyl formate. In addition, 1.0 mol / 3-picoline as a solvent, 0.050 mol of mercury bromide as a catalyst and 0.02 mol of hydroquinone as a polymerization inhibitor are added in each case per mol of vinyl formate. Carbon monoxide in a content of 20 volume percent nitrogen is introduced into the autoclave under pressure, and the reaction is carried out 3.0 hours at 230 ⁰ C and a pressure of 600 atm. The reaction product is worked up to give 9.30 g (0.129 mol) of acrylic acid. This yield corresponds to a conversion of 46.4% based on the starting formic acid ester.

Example 33

The same autoclave as used in Example 26 is charged with 20.0 g (0.333 mol) of methyl formate. Then 1.0 mole of N-methylpyrrolidone and 0.050 mole of mercury acetate are added per mole of methyl formate. Carbon monoxide is introduced under pressure. The reaction is carried out for 1 hour at a pressure of 300 atm and a temperature of 220 ⁰ C. As a result, acetic acid is obtained in a yield of 1.44 g (0.024 mol),

representing a turnover of 7.2 ° / _0th based on the starting formic acid ester.

Example 34

The same autoclave as used in Example 26 is charged with 20.0 g (0.333 mol) of methyl formate loaded. In addition, 1.0 mol of N-methylpyrrolidone, 0.030 mol of zinc carbonate and 0.070 mol Iodine was added per mole of methyl formate. Carbon monoxide gas with a content of 8 percent by volume Hydrogen is introduced into the autoclave under pressure and the reaction is continued for 1 hour carried out a pressure of 300 atü and a temperature of 220 ° C. As a result, acetic acid becomes in obtained a yield of 13.6 g (0.227 mol), which corresponds to a conversion of 68.1%, based on the starting methyl formate, is equivalent to.

B e i s ρ i e 1 35

The reaction as carried out continuously for 24 hours using the same reaction vessel in Example 3 under the following conditions: Pressure 300 atm Temperature 230 ⁰ C, feeding rate of methyl formate 298 g per hour (4.97 moles per hour), liquid space velocity 1.02 h ~ ^l and carbon monoxide circulation rate 102 Nl / h (4.42 mol per hour). As a solution

medium is N-methylpyrrolidone in a ratio of 1.1 moles per mole of methyl formate and as a catalyst Mercury iodide in a ratio of 0.032 moles per mole of methyl formate in the form of a 11.8 percent by weight Solution in N-methylpyrrolidone, which is used as a solvent, introduced. Additionally

methyl acetate is also introduced at a rate of 11 grams per hour (0.15 moles per hour). As a result, acetic acid is obtained in a yield of 242 g per hour (4.04 mol per hour). This yield corresponds to a conversion of 81.2 ° / o> ^ ^e "coated on the imported methyl formate.

1 sheet of drawings

Claims (3)

Patent claims: 1. Process for the preparation of a carboxylic acid of the general formula RCOOH where R is a saturated or unsaturated, acyclic or cyclic aliphatic hydrocarbon group, is an aryl, aralkyl or heterocyclic group, characterized in that that one has a formic acid ester of the general formula HCOOR wherein R has the meaning given above, in the presence of carbon monoxide and one Catalyst consisting of a metal or a metal compound of group Hb or VIII of the periodic table in an organic polar solvent, consisting of carboxamides, heterocyclic amines, nitriles or ketones, at a temperature of 100 to 300 ° C and below heated under increased pressure. 2. The method according to claim 1, characterized in that the reaction is carried out at a Total pressure of at least 80 atm, with the partial pressure of carbon monoxide in The presence of an inert gas is at least 50 atmospheres. 3. The method r> ach one of the preceding claims, characterized in that the Catalyst in the reaction mixture in an amount from 0.2 to 200 mg atoms. calculated as the metal per mole of the starting acid formate used. According to the invention, this object is achieved by using a formic acid ester the general formula